Introduction Polycystic ovary syndrome (PCOS) is considered as one of the current disorders of the endocrine system in women of reproductive age (1-3). The epidemiological studies indicated that the incidence of PCOS varies in the world with a range of 2.2% to 26% (2,4). Such incidence is 43% to 46% in the United States, 37.4% in Germany, and 16% in Italy (5). The typical complications of PCOS include polycystic ovaries, elevated luteinizing hormone, hyperandrogenism, chronic anovulation along with oligoamenorrhea, obesity, and infertility (6). PCOS could be taken into account as a metabolism-centered syndrome such as insulin resistance syndrome or some other risk factors, including cardiovascular diseases, hypertension, and/or dyslipidemia (7). Although the mechanism underlying the pathogenesis of PCOS is still elusive, this syndrome is concomitant with hormonal perturbation, such as a diminished concentration of progesterone and heightened levels of testosterone, estrogen and luteinizing hormone (8-10). In patients afflicted with both hyperandrogenism and PCOS, there is a strong association between the hyperinsulinemia and hyperandrogenism as the concentration of insulin shows a strong correlation with adrenal steroid excretion (11). On the other hand, in patients with PCOS, hyperinsulinemia is concurrent with heightened levels of low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), triglyceride, total cholesterol (12) and reduced level of high-density lipoproteins (HDL) (13). Additionally, besides insulin resistance, the metabolism of lipid in females suffered from PCOS may be altered by ovarian-or adrenalexcretion of sex steroid hormones. Effects of sex steroids Abstract Objectives: Polycystic ovary syndrome (PCOS) has been considered as one of the most common endocrine diseases among the females in their regenerative age with a prevalence range of 5 to 21%. However, the purpose of the present study was to investigate the protective effect of Galega officinalis on metabolic as well as hormonal parameters in a rodent model of PCOS. Materials and Methods: Thirty-two Wistar female rats were used (n=8/group) in the study consisting of healthy control and experimental groups. The experimental groups were divided into 3 subgroups, including rats with PCOS which received no treatment (G1), PCOS group in which G. officinalis extract was administered daily at a dose of 200 mg/kg/orally (G2) for 2 weeks, and PCOS group in which G. officinalis extract was administered daily at a dose of 400 mg/kg/orally (G3) for 2 weeks. In all experimental groups, a single intramuscular injection of estradiol valerate led to inducing PCOS. After the end of treatment period, rats in all of the studied groups were anesthetized with ketamine/xylazine (5/1 mg/kg), then the blood samples obtained and their serum samples were applied for testing the fasting blood sugar (FBS), insulin, aromatase, and follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and estrogen. The ovaries of rats were removed and fi...